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YOU are better than YOU think. Show
yourself how:
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Read logic
chapters 1 to 5 in online volume Three
Skills for Algebra for greater skills & confidence
in work
and study
Learn to read notes and textbooks like
a lawyer, so that no nuance, no subtlety and no clause escapes your
attention. |
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Logic
chapters 1 to 5 re- appear not in sequence, as is or longer,
in Volume 1A, Pattern Based
Reason, Bon Appetite.
Logic
Mastery
Amazing, Amusing, Amorous, Delicious, Delightful, Edifying,
Strengthening Elixir.
It eases work & learning difficulties Makes the hard easier. Opens eyes.
Leads to greater precision.
in reading and
writing
Logic
mastery makes the hard, easier. Logic
mastery leads to better, stronger and richer comprehension. Logic
mastery improves reading and writing. Logic
mastery ease learning difficulties. Logic
mastery gives a headstart. In sum, logic
mastery will develops critical thinking, improve reading and writing,
and give a firmer base for work and studies at many levels. Good luck.
After logic,
(a) continue reading Three
Skills for Algebra, chapters 8 to 14 and do so alongside site area on solving
liinear Equations ; or (b) see this calculus
starter lesson and Volume 3, Why
Slopes & More Math, chapters 2 to 6;
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Caution: Site advice is approximately
correct, for some circumstances, not all. That leaves room for thought |
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What may be learnt and when depends on how skills
and concepts are developed. Making the hard easier and clearer will allow
earlier & richer development of skills and concepts.
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Addition Preliminaries
Physical Interpretation
Addition Via Counting
To illustrate this, take for instance two bags of marbles. Say
one bag has 13 marbles and another 15. Ask your child to put the two bags
together, and count how many there are. Now take two bags, one with 13 buttons
and another with 15 buttons. Ask your child again to count how many there are.
This shows the total number of objects does not depend on their type or kind.
Redo this addition experience with varying numbers.
Addition via Counting may lead to the additon table
| + |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
| 2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
| 3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
| 4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
| 5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
| 6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
| 7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
| 8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
| 9 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
If you do or review it with a student, observe how
adding n+1 to number is one more than adding n to the number. That
provides a mechanism for filling in the table by rows (horizontally
from right to left) and by columns (vertically from top to bottom).
Students should know the sums of all pairs of digits
from 1 to 9, as well as how to add 0 and 10 to a single digit number.
Filling in the addition table is a good exercise.
Addition with Decimals - How to Justify
Besides column methods for addition shown below, there are column methods
for subtraction, multiplication and even long division. All methods, some more
directly than others, take advantage of decimal place value.
Single to Triple Digit Examples - with carries
Provide the following experiences (and similar ones).
-
By counting 3 ones added to 4 ones is 7 ones. On
paper this can be written in the shorthand form
3
+ 4
----------
7
----------
-
By counting 8 ones added to 7 ones yields 15 ones.
On paper this can be written in the shorthand form
8
+ 7
----------
15
----------
-
By counting, 12 ones added to 25 ones is 37 ones or
three tens and 7 ones. On paper this can be written in the shorthand
form
12 (read backwards: 2 ones plus 1 ten )
+ 25 (read backwards: 5 ones plus 2 tens)
------ added together gives
37 7 ones plus 3 tens
------
244 ( 4 ones plus 4 tens plus 2 hundreds )
85 ( 5 ones plus 8 tens)
----- added together gives
9 ones plus 12 tens plus 2 hundreds
-----
But the 12 tens is the same as 2 tens plus 1 hundred.
Thus replacement suggests the result
____________________________________\_
/
244 (read 2 ones plus 4 tens plus 2 hundreds ) |
85 (read 5 ones plus 8 tens) |
---------- added together gives |
329 9 ones plus 12 tens plus 3 hundred |
--------- or 9 ones plus 2 tens plus 2+1 hundreds |
1 or 9 ones plus 2 tens plus 3 hundreds \|/
/____________________________________________
\
shorthand + Longhand Representations, respectively,
of the addition
The one in the last row denotes a carry. The on the left
and the words on the right represent the same number. Here the shorthand
expressions requires less work to write, but its justification requires
a knowledge of the longhand form. In the following examples, we write
the shorthand form, then do the calculation with the help of the
longhand representation and lastly return to the shorthand form. With
practice, the long representation and explanation of the shorthand will
be understood, and it need not be written down. The calculation is then
done and represented via its shorthand representation.
Examples:
Addition without Conversions (Carries)

Steps
- add units
- add tens
- add hundreds
Conclusion: 243 + 452 = 695.
Addition with Conversions (Carries)


Steps
- Add units: 9 and 6 give 15 = 5 + 10 or a 5 in the unit column with one ten
to carry over into the ten's column.
- Add tens: 5 + 2 + the 1 from the carry give 8.
- Add hundreds: 4 + 8 hundreds give 10 + 2 hundreds or 2 in the hundred
column with a one thousand to carry over to into the thousands column.
- Add thousands. the carry of 1 + 2 + 4 = 7. Done
- Conclusion: 2459 + 4826 = 7285.
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www.whyslopes.com
Number Theory
Start of Number Theory
Origins of Counting or Tallying
Adding Wholes
Multipling Wholes
Distributive Law Preamble
Distributive Law for Wholes
Consequences
More Consequences
What is a Fraction
Compound Fractions
Number Theory
Continued
Decimal Place Value Place Value Reinforcement Comparison Method Addition Method Subtraction Methods Multiplication Methods Division Methods Remainder Arithmetic I Primes & Composites Primes Factorization Theorem Primes & Composites Prime Factorization Aids Prime Factorization Examples Counting Whole No. Factors Arithmetic Videos Square Roots & Primes Long Division Continued Fractions & Decimals Fractions as Decimals 1 = 0.999 Recurring Infinite Decimals Expansion Arithmetic Ratio of Simple Fractions Ratio of Decimal Fractions Unsigned Reals Numbers Signed Coordinates Plane Vectors Horizontal Vectors Adding Vector Multiplies Adding Signed Numbers Multiplying Signed Numbers Distributive Law for Reals Real Numbers Axioms Remainder Arithmetic II
Related Site Pages:
For online automated help in senior high school maths & calculus,
visit quickmath.com For Automatic
Calculus and Algebra Help with derivatives, integrals, graphs, linear equations,
matrix algebra, visit calc101.com
With overlap, each site quickmath
& calc101offers a different range of
services, some free, some not, all based on webmathematica. Good luck
Food for thought: Try the Twiddla
Whiteboard. In principle, it allows
to people to draw and chat together online on a copy of this webpage or a clean
sheet. The chat may be via text or audio. Visit www.twiddla.com
to set up whiteboards to work with the webpage of your choice..
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